A directive of the European Parliament and of the Council of the European Union on the activities and supervision of IORPs. The directive was intended as a first step in developing an internal market for occupational retirement provision throughout the European Union (EU). Key provisions include the introduction of a prudent person rule for investing pension assets, and a requirement for schemes to invest predominantly on regulated markets. Pension schemes must also be fully funded at all times, subject to a limited recovery period. Member states had to implement the IORP directive by 23 September 2005. In the UK, the government implemented the IORP directive through the Pensions Act 2004. See Direcitve 2003/41/EC of the European Parliament and of the Council of 3 June 2003 on the activities and supervision of institutions for occupational retirement provision.